Cracked Transfer Case

[jbmazda6]

What's interesting about this situation, and I don't think I've seen this from reading, is that I have a cracked transfer case but I was able to drive the car home from the drag strip after I noticed a gear oil smell and retired the car for the night. At the time I did not know the case was cracked as I never heard any weird sounds or felt anything abnormal. I noticed a large puddle of gear oil the next morning under my car and just now got around to checking out the problem (picture of the crack attached). Hoping to pull the t-case today so I can do some investigation but I think the internals will all be salvageable based off the fact that it drives without issue.

Just wanted to add another thread with some details to help other folks out in the future as well as hear if any of you have had similar issues. If the internals are good I'll be on the lookout for a good cx-7 case or if one of you has a good speed6 case with bad internals that I could swap mine into let me know.

Thanks for the help.

P.S. Been a long time since I've been on here, hopefully I see some familiar names.

[jbmazda6]

Finished pulling the transfer case a while ago and got some pictures. Looks like all of the bearing caps are still in good shape but it fractured from a locating pin to a bolt hole on the drivers side of the case. A piece of metal must have gotten into the case because one of the gears has uniform damage on each tooth. Found reminiscence of this in the oil and on the oil drain plug.

@phate; I saw you had your transfer case blow up on you years ago. Any thoughts?

[Fstrnyou]

Gah dang man.

May as well upgrade the bearing caps.

[phate]

Originally Posted by jbmazda6 phate I saw you had your transfer case blow up on you years ago. Any thoughts?

Looks like most other failures - the bevel gears put an axial load on that shaft and it blows out the side like that. That end needs reinforcement.

[phate]

Originally Posted by Fstrnyou Gah dang man. May as well upgrade the bearing caps.

Caps don't have anything to do with this one.

In the picture of the broken section, where you can see the inside wall, you can see the surface where it is acting as the thrust bearing for that shaft. So the axial load is being completely held by that surface, not the inner surface of the bearing cap.

I've said for a long time that I don't think bearing caps are the primary failure mode.

Sent from my SM-G960U using Tapatalk

[Jeff23spl]

is there a fix for this one ? (I mean to avoid this)

[jbmazda6]

Originally Posted by phate Looks like most other failures - the bevel gears put an axial load on that shaft and it blows out the side like that. That end needs reinforcement.

As I've continued to read I see that my failure is similar to many others. I have yet to find one with what's seemingly minor damage which is why I'm posting for awareness in the hopes we, as a forum, can draw some potentially new conclusions or solidify existing ones.

Originally Posted by phate Caps don't have anything to do with this one. In the picture of the broken section, where you can see the inside wall, you can see the surface where it is acting as the thrust bearing for that shaft. So the axial load is being completely held by that surface, not the inner surface of the bearing cap. I've said for a long time that I don't think bearing caps are the primary failure mode. Sent from my SM-G960U using Tapatalk

I would agree as far as caps go. I personally can't justify the cost when there is a high probability that the case will fail in another mode and damage the caps in the process.

If anyone wants more/better pictures please let me know. I can also transfer this information to an existing thread if that would be beneficial.

I'll be going down the cx-7 pto route as the options are getting slimmer each year that passes. I will say that this pto lasted 100+ runs at the drag strip as well as daily abuse for the past 8 years (at least). Not too bad.

[phate]

Originally Posted by jbmazda6 As I've continued to read I see that my failure is similar to many others. I have yet to find one with what's seemingly minor damage which is why I'm posting for awareness in the hopes we, as a forum, can draw some potentially new conclusions or solidify existing ones.

Yeah, as cool as catastrophic damage is to look at, it's usually way harder to sort out what failed first. This is another piece of evidence that we need to reinforce that end of the case.

Where that end nests into the transmission housing makes it tough to add material, but if someone wanted to weld on extra material, they could. If you never intend to remove that screw in cover, you could add quite a bit of strength adding material across the access hole.